listed species are those with: 1) 6 to fewer than 20 extant sites, or 2) 1,000 to fewer than 3,000 individuals, or 3) restricted to not less than 4 or more than 7 U.S.G.S. 7 ½ minute topographical maps, or 4) listed as threatened by U.S. Department of Interior.

Federal Protection:
Not Listed

State Rarity Rank:S2

A State Rarity Rank of S2 means: This plant is threatened/imperiled in New York because of rarity (typically 6-20 populations or few remaining individuals) or is vulnerable to extirpation from New York due to biological factors.

Global Rarity Rank:G5

A Global Rarity Rank of G5 means: This species is demonstrably secure globally, though it may be quite rare in parts of its range, especially at the periphery.

Did you know?
The species name of this spiny-fruited grass derives from the Latin "tribulus", the name for the antipersonnel weapon called a caltrop. This weapon usually consists of four spikes, one of which always points upward when supported on the ground by the other three (Wikipedia contributors). While the Civil War raged on in 1862 William H. Leggett collected New York's first specimen of this species on Staten Island. The specimen is now in the collection of the New York Botanical Garden.

There are 8 known populations, but almost all of them have 100 plants or less. They need disturbed sands to thrive, but they are also subject to direct destruction by beachgoers, especially since they occur on popular tourist beaches. There are about 20 historical occurrences.

The short-term trend seems stable with little fluctuation over the years. Populations would have been expected to grow with more protection of the beach for rare shorebirds, but this does not seem to have happened.